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Charge your electric car with a balcony power plant and reduce electricity costs.
Charging an electric car with a balcony solar system sounds like the perfect combination of affordable solar power and electric mobility. However, there are a few technical hurdles between this wish and reality, which we, as experienced electrical engineers, will address openly. In this guide, you'll learn how much range a plug-in solar system actually contributes, why direct charging at a wallbox doesn't work, and what solutions still allow you to get solar power into your vehicle. We'll also show you when upgrading to a larger system really makes financial sense.
Does charging an electric car with a balcony power plant even work?
Depending on its design, a balcony power plant feeds 600 to 800 W into your home's electrical grid. An electric car requires significantly more power to charge. Therefore, a balcony power plant doesn't charge your electric car directly into its battery in the traditional sense of solar power. At PVundSO, we encounter this question almost daily, so a realistic look at the technology is worthwhile.
The solar power is initially directed to where it is currently being used in the household. If your car is connected to the grid via a wall socket or wallbox, the balcony power plant only covers a portion of this load. The vehicle draws the rest from the public grid. This interplay between self-consumption and grid power consumption determines the actual benefit.
Why direct charging at the wallbox doesn't work
A wallbox only starts charging at a minimum power output of approximately 1,4 kW single-phase; many common models charge three-phase at 11 kW. These values are significantly higher than what a plug-in solar system delivers. A balcony solar power plant alone cannot reliably operate a wallbox, as even a passing cloud could interrupt the charging process.
How much electricity can a balcony power plant supply for an electric car?
To give you a sense of scale, let's look at some concrete figures. An 800W balcony solar power system generates around 3 to 5 kWh on a sunny day. With a consumption of approximately 17,5 kWh per 100 km, this equates to a daily range of roughly 15 to 33 km, assuming all the generated electricity is used to power the vehicle.
| Balcony Solar Panel | Yield per sunny day | Daily range |
|---|---|---|
| 600 W | 2 to 4 kWh | 11 to 22 km |
| 800 W | 3 to 5 kWh | 15 to 33 km |
| 2000 W module power | 6 to 9 kWh | 34 to 51 km |
Over the course of the year, these peak values become less significant because clouds, seasons, and shading reduce the yield. A realistic figure for an 800-watt system is around 700 kWh per year, which equates to approximately 4.000 km of driving. This means a balcony solar power system covers roughly 16 percent of the electricity needs of an average electric car.
Expressed in euros, this saves you approximately €100 in charging costs per year. While not a spectacular figure, it's a solid contribution that helps to offset the initial purchase price over the system's lifespan. We explain the technical workings of such a system in the article " How does a balcony power plant work?".
Power outlet or wallbox as a way to charge the battery
At home, you can charge your vehicle in two ways. The included charging cable, plugged into a standard household socket, draws around 2,3 kW, while a permanently installed wallbox typically charges at 11 kW. Both connection methods require more power than a balcony solar power system can supply , further emphasizing the importance of self-consumption.
It's important to understand that your balcony power plant isn't directly connected to the wallbox. The plug-in solar system feeds power into the home's electrical grid, and the car draws its electricity from the same grid. Whichever method you choose, the solar power only covers the portion that is generated at any given time.
This leads to a practical rule: Slow charging via a standard household outlet during the day allows a larger proportion of solar power to be used than a fast wallbox charge, which is completed in a short time. Therefore, those who have the time benefit from leisurely charging during the peak solar hours at midday.
Balcony power plant: Charging an electric car via self-consumption
The greatest benefit is indirect. Your balcony power plant reduces the household's electricity consumption, and the saved grid electricity is theoretically available for charging the car. Those who charge during the day get the most out of this logic , because then the sun and the charging process coincide.
In practice, this means consciously scheduling charging for midday hours. If your vehicle is parked at home on weekends or during the day while you're working from home, the solar power flows directly into the battery instead of being fed unused into the grid. Even a simple timer for the charging process shifts some of the demand to peak solar hours.
The better you coordinate your energy production and consumption, the higher your self-consumption rate will be. A Wi-Fi-enabled balcony power plant helps with this, because you can monitor the current output and plan the charging start accordingly. This way, you can turn a small system into a measurable benefit at your wall socket.
Save solar power for the evening with storage
Many people only charge their cars in the evening, long after the sun has set. This is precisely where a small battery storage system comes in. A 1,5 to 2 kWh storage unit connected to a balcony power plant buffers the electricity generated during the day and releases it again in the evening hours when the vehicle is plugged in.
This reduces your grid consumption precisely when it would otherwise be highest. A suitable storage system can be found in our "Balcony Power Plant with Storage" category ; larger units for the whole house are shown under "Electricity Storage".
It must be said honestly that a small storage system doesn't even come close to covering the electricity consumption of a car. It smooths out the daily energy usage and increases self-consumption, but it doesn't replace a larger system. Nevertheless, this combination is attractive for occasional short trips and as a supplement to household energy use.
When does a PV system become more worthwhile for charging an electric car?
Anyone who wants to charge their vehicle primarily with their own solar power will need a rooftop system. True solar charging, including surplus charging, becomes worthwhile with a photovoltaic system of around 5 kWp and a home battery storage system. Only then is enough power available during the day to cover a significant portion of the charging energy with self-generated energy.
In this setup, a wallbox with a surplus charging function takes over the control. It prioritizes charging the car with electricity that is not currently needed in the household and supplements it with grid power as required. This prevents interruptions and still prioritizes using solar power for the vehicle.
You'll find the perfect entry point into this size range in our PV systems category , optionally with or without storage. We'd be happy to advise you on the output that best suits your driving profile and roof area. The higher the solar-generated portion, the faster the system will pay for itself through the savings on charging costs. A balcony power plant remains a good first step, which you can later supplement with a larger system.
Selecting a suitable balcony power plant for electric car owners
If you want to charge your electric car with a balcony power plant and maximize your energy yield, the installed module capacity is the most important factor. Currently, systems feed up to 800 W into the grid, but can be equipped with higher module capacities of up to 2000 W. More modules mean more energy production on cloudy days and during off-peak hours.
Also, look for integrated Wi-Fi monitoring so you can coordinate energy generation and charging start. High-performance complete sets like the 2000W balcony power plant with 4 solar panels provide a solid foundation, while the MAXI balcony power plant with storage further covers evening energy needs.
A favorable south-facing orientation and an unshaded location significantly increase the annual yield. An east-west orientation, on the other hand, distributes generation throughout the day , providing electricity in both the morning and afternoon, which suits the typical charging habits of many commuters. Our balcony power plant category offers an overview of all options, from compact mini-solutions to high-performance systems . This way, you can find the model that suits your consumption and your building's structural possibilities.
Frequently asked questions about charging electric cars with a balcony power plant
Can I fully charge my electric car with a balcony power plant?
No, a balcony power plant only covers part of the charging needs. With an annual yield of approximately 700 kWh, around 4.000 km are possible, which is roughly 16 percent of typical electricity demand. For the rest, grid power is still necessary.
Do I need a special wallbox?
You don't need a wallbox to charge directly from your balcony solar system, as the power output is too low. A wallbox with a surplus charging function only becomes worthwhile when combined with a larger rooftop system. For occasional charging, the included charging cable plugged into a fused outlet is perfectly sufficient.
Is a battery storage system worthwhile for charging an electric car?
A small storage system shifts solar power to the evening hours and increases self-consumption. However, it does not replace a larger system, but rather complements the household system effectively and reduces evening grid consumption.
How many kilometers per year are realistic?
With an 800W system, approximately 4.000 km per year is realistic, provided you primarily charge during the day. This corresponds to annual savings of around €100 in charging costs. This figure can be further increased with higher module output and a suitable battery storage system.
Conclusion
A balcony power plant is a sensible and affordable way to reduce electricity costs for your electric car, but it's not a replacement for charging from the grid. You'll benefit most from self-consumption and consciously charging during midday hours. If you want to primarily power your vehicle with solar energy, a rooftop system with a battery storage unit is significantly better. However, as a starting point, a balcony power plant remains a simple and quick way to save on charging costs. We'd be happy to work with you to find the right solution for your needs. Simply contact us for a free consultation.
